Three-dimensional molded circuit component

ABSTRACT

A three-dimensional molded circuit component, includes: a base member which includes a metal part and a resin part; a circuit pattern which is formed on the resin part; and a mounted component which is mounted on the base member, and is electrically connected to the circuit pattern. The resin part includes a resin thin film as a portion thereof, which includes a thermoplastic resin, of which a thickness is in the range of 0.01 mm to 0.5 mm, and which is formed on the metal part. The mounted component is arranged on the metal part via the resin thin film.

CROSS REFERENCE TO RERATED APPLICATION

This application is a Divisional Application of application Ser. No.16/170,829, filed Oct. 25, 2018, which in turn is a ContinuationApplication of International Application No. PCT/JP2017/016594 which wasfiled on Apr. 26, 2017 and claiming priority to Japanese patentApplication No. 2016-089522 filed on Apr. 27, 2016, the entiredisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a three-dimensional molded circuitcomponent in which a circuit pattern is formed on a base member(substrate, base material), which includes a metal part (metal portion)and a resin part (resin portion).

Description of the Related Art

In recent years, MIDs (Molded Interconnected Devices) have been put topractical use in smart phones, and hereafter, are anticipated to haveextended applications in the field of automobiles. The MID is a devicein which a three-dimensional circuit is formed by a metallic film on asurface of a molding (molded body, molded product), and is capable ofcontributing to making a product light-weight and thin, and to reductionof number of components.

An MID in which a light emitting diode (LED) is mounted has beenproposed. Since an LED generates heat when an electric power issupplied, it is necessary to exhaust the heat from a rear surface,thereby making it significant to improve a heat dissipation property ofthe MID.

In Patent Literature 1 (Japanese Patent No. 3443872 Publication), acomposite component in which an MID and a heat dissipating material areintegrated, has been proposed. According to Patent Literature 1, thiscomposite component has achieved both, the heat dissipation property andthe small-sizing of MID. However, an adhesion between a metal having ahigh heat dissipation property and a resin material is low in general.In Patent Literature 2 (Japanese Patent Application Laid-openPublication No. 2009-6721 corresponding to U.S. Patent ApplicationPublication No. 2006/127684), a nano molding technology (NMT) forimproving the adhesion between a metal and a resin material has beenproposed. In the nano molding technology (NMT), a surface of a metal isroughened chemically, and upon providing asperities of nano level to theroughened surface, the roughened surface is integrated with a resinmaterial. According to Patent Literature 2, when the nano moldingtechnology (NMT) is used, a contact area of a joint (bonded, cemented)surface of the metal and the resin material is enlarged remarkably,thereby improving the adhesion, and the metal and the resin material aresuppressed from being exfoliated (detached, peeled off) in a heat-shocktest, and the heat dissipation property is also improved. In PatentLiterature 3 (Japanese Patent No. 5681076 Publication), aheat-dissipating lamp for LED which is manufactured by joining(cementing) a metal and a resin material, by using the nano moldingtechnology (NMT) has been proposed.

However, in recent years, electronic devices have been becomingsmall-sized with an improved performance. High densification and highfunctionality of MIDs used in the electronic devices have also beenprogressed, and higher heat dissipation property of the MIDs has beensought. The present teaching is aimed at solving these problems, andprovides a three-dimensional molded circuit component which has a highheat dissipation property, and moreover, which is easy to mold and has ahigh productivity.

SUMMARY OF THE INVENTION

According to a first aspect of the present teaching, there is provided athree-dimensional molded circuit component, including a base memberwhich includes a metal part and a resin part, a circuit pattern which isformed on the resin part, and a mounted component (mounted part) whichis mounted on the base member and is electrically connected to thecircuit pattern, wherein the resin part includes a resin thin film as aportion thereof, which includes a thermoplastic resin, of which athickness is in the range of 0.01 mm to 0.5 mm, and which is formed onthe metal part, and the mounted component is arranged (disposed) on themetal part via the resin thin film.

In the present aspect, an area of the resin thin film per mountedcomponent that is arranged on the resin thin film may be in the range of0.1 cm² to 25 cm². The base member may be an integrated molding of themetal part and the resin part.

According to a second aspect of the present teaching, there is provideda three-dimensional molded circuit component including a base memberwhich includes a metal part and a resin part, a circuit pattern which isformed on the resin part, a resin thin film which is formed on the metalpart, and which includes one of a thermosetting resin (heat-curableresin) and a photo-curable (photo-curing) resin, and a mounted componentwhich is mounted on the resin thin film, and is electrically connectedto the circuit pattern.

In the present aspect, a thickness of the resin film may be in the rangeof 0.01 mm to 0.5 mm. Moreover, the resin thin film may contain a heatdissipating material having an insulation property.

In the first aspect and the second aspect of the present teaching, theresin part may include foamed cells, and moreover, the resin thin filmmay not include the foamed cells essentially (practically). The metalpart may be a heat dissipating fin. The mounted component may be an LED.A nickel phosphorous film may be formed on a surface of the metal part.

In the first aspect and the second aspect of the present teaching, onthe base member, a recess may be defined by a side wall formed by theresin part and a base (bottom) formed by the resin film, and the mountedcomponent may be mounted in the recess, and a shape and an area of thebase (bottom) of the recess may be substantially same as a shape and anarea of a surface of the mounted component which is in contact with thebase (bottom).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic diagram of a three-dimensionalmolded circuit component manufactured according to a first embodiment.

FIG. 2 is an enlarged view of a periphery of a mounted component in thecross-sectional schematic diagram of the three-dimensional moldedcircuit component shown in FIG. 1.

FIG. 3 is a cross-sectional schematic diagram of another example of thethree-dimensional molded circuit component manufactured according to thefirst embodiment.

FIG. 4A and FIG. 4B are cross-sectional schematic diagrams of stillother examples of the three-dimensional molded circuit componentsmanufactured according to the first embodiment.

FIG. 5 is a cross-sectional schematic diagram of a three-dimensionalmolded circuit component manufactured according to a modified embodiment1 of the first embodiment.

FIG. 6 is a cross-sectional schematic diagram of a three-dimensionalmolded circuit component manufactured according to a modified embodiment2 of the first embodiment.

FIG. 7 is a cross-sectional schematic diagram of a three-dimensionalmolded circuit component manufactured according to a second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT First Embodiment

(1) Three-Dimensional Molded Circuit Component

In the present embodiment, a three-dimensional molded circuit component100 shown in FIG. 1 will be described. The three-dimensional moldedcircuit component 100 includes a base member 10 which includes a metalpart 11 and a resin part 12, a circuit pattern 14 which is formed on theresin part 12 by a plating film, and a mounted component 15 which ismounted in a recess 13 formed in the base member 10, and is electricallyconnected to the circuit pattern 14. As shown in FIG. 2, a side wall 13a of the recess 13 is formed by the resin part 12, and a base (bottom)13 b of the recess 13 is formed by a resin thin film 16. The mountedcomponent 15 is arranged (disposed) on the metal part 11 via the resinthin film 16. In the present embodiment, the resin thin film 16 is aportion of the resin part 12. Therefore, the resin thin film 16 isformed of the same resin as that in the resin part 12.

As the base member 10, it is possible to use an arbitrary base member,provided that the base member is a composite body in which the metalpart 11 and the resin part 12 are joined, and in the present embodiment,an integrated molding in which the metal part 11 and the resin part 12have been molded integrally is used. Here, ‘molded integrally’ refers toa process of joining members at the time of molding the members (atypical insert molding), and not sticking (gluing) or joining themembers that have been prepared separately (secondary gluing ormechanical joint).

The metal part 11 dissipates heat generated by the mounted component 15mounted on the base member 10. Therefore, it is preferable to use ametal having a heat dissipation property for the metal part 11, and itis possible to use metals such as iron, copper, aluminum, titanium,magnesium, and stainless steel (SUS). Among these metals, it ispreferable to use magnesium and aluminum from a point of view of weightreduction, heat dissipation property, and cost. These metals may be usedindependently or may be used upon mixing two or more types.

The resin part 12 insulates the circuit pattern 14 formed thereon andthe metal part 11 which is an electrical conductor. For the resin part12, it is preferable to use a thermoplastic resin with a high meltingpoint which is heat-resistant and has a solder reflow resistance. Forinstance, it is possible to use aromatic polyamides such as nylon 6T(PA6T), nylon 9T (PA9T), nylon 10T (PA10T), nylon 12T (PA12T), nylonMXD6 (PAMXD6) and the like, and alloy materials thereof, polyphenylenesulfide (PPS), liquid crystal polymers (LCP), polyether ether ketone(PEEK), polyether imide (PEI), and the like. These thermoplastics may beused independently or may be used upon mixing two or more of these.Moreover, in the present embodiment, the resin thin film 16 on which themounted component 15 is mounted by soldering is a portion of the resinpart 12. Therefore, it is preferable that the melting point of a resinto be used for the resin part 12 is 260° C. or more in order to enablesoldering, and it is more preferable that the melting point is 290° C.or more. However, the melting point is not restricted to theabovementioned temperatures in a case of using a low-temperature solderfor mounting the mounted component 15. Moreover, from a point of view ofdimensional stability and improvement in rigidity, the abovementionedthermoplastic resins may contain an inorganic filler such as glassfiller, a mineral filler, and the like.

It is possible to let the size and shape of the metal part 11 and theresin part 12 to be an arbitrary size and shape in accordance with anapplication of the three-dimensional molded circuit component 100. Thecircuit pattern 14 being formed three-dimensionally (stereoscopically)on the resin part 12, the resin part 12 either has a plurality ofsurfaces or has a three-dimensional surface including a sphericalsurface and the like. In the present embodiment, the resin part 12 whichis a thermoplastic-resin layer is molded integrally on the metal part 11which is a curved metal plate. Accordingly, the thermoplastic-resinlayer (resin part 12) is curved along the metal plate (metal part 11)that is curved, and has a plurality of surfaces. From a point of view ofthe heat dissipation property, a thickness t₁₁ of the metal plate (metalpart 11) is 0.5 mm or more, and it is preferable that the thickness t₁₁is 1 mm or more, whereas from a point of view of reduction in cost andweight, and improvement in machining, the thickness t₁₁ is 20 mm orless, and it is preferable that the thickness t₁₁ is 10 mm or less.Here, the thickness t₁₁ of the metal plate (metal part 11) refers to athickness in a direction perpendicular to an interface with the resinpart 12. From a point of view of ease of molding, a thickness t₁₂ of thethermoplastic-resin layer (resin part 12) is 0.5 mm or more, and it ispreferable that the thickness t₁₂ is 1 mm or more, whereas, from a costpoint of view, the thickness t₁₂ is 5 mm or less, and it is preferablethat the thickness t₁₂ is 3 mm or less. Here, the thickness t₁₂ of thethermoplastic-resin layer (resin part 12) refers to a thickness of aportion other than the recess 13 on which the mounted component 15 is tobe mounted, and is a thickness in a direction perpendicular to aninterface with the metal part 11. Moreover, the thermoplastic-resinlayer (resin part 12) being provided for insulating the circuit pattern14 and the metal part 11, the thermoplastic-resin layer (resin part 12)may not be provided to a portion on which the circuit pattern 14 has notbeen formed.

In the present embodiment, the metal part 11 is not restricted to ametal plate, and it is also possible to use a metal having a complexshape molded by die-casting.

Since the circuit pattern 14 is to be formed on the resin part 12 whichis an insulator, it is preferable that the circuit pattern 14 is formedby electroless plating. Therefore, the circuit pattern 14 may include anelectroless plating film such as an electroless nickel phosphorousplating film, an electroless copper plating film, an electroless nickelplating film and the like, and among these, it is preferable that thecircuit pattern 14 includes the electroless nickel phosphorous platingfilm. When the circuit pattern 14 is formed of the electroless nickelphosphorous plating film, it is possible to simultaneously form a nickelphosphorous film (electroless nickel phosphorous plating film) 18 on asurface of the metal part 11, and it is possible to improve a corrosionresistance of the metal part 11. In the circuit pattern 14, another typeof electroless plating film or electrolytic plating film may be stackedin addition, on the electroless plating film. By making a totalthickness of the plating film thick, it is possible to make small anelectrical resistance of the circuit pattern 14. From a point of view oflowering the electrical resistance, it is preferable that the platingfilm to be stacked on the electroless plating film is an electrolesscopper plating film, an electrolytic copper plating film, anelectrolytic nickel plating film, and the like. Moreover, for improvinga solder wettability of the plating film in order to withstand thesolder reflow, a plating film of a metal such as tin, gold, silver, andthe like may be formed on the outermost surface of the circuit pattern14.

The circuit pattern 14 is formed three-dimensionally along a surfacehaving a three-dimensional shape including a spherical surface and thelike or over the plurality of surfaces of the resin part 12. The circuitpattern 14 is a three-dimensional electric circuit having conductivity,which is formed three-dimensionally along the surface having athree-dimensional shape including a spherical surface and the like orover the plurality of surfaces of the resin part 12. Since the circuitpattern 14 is to be electrically connected to the mounted component 15mounted in the recess 13, the circuit pattern 14 may be formed on theside wall 13 a and the base (bottom) 13 b of the recess.

The mounted component 15 is electrically connected to the circuitpattern 14 by a solder 17, and becomes a heat-generating source bygenerating heat by the supply of electric power. An LED (light emittingdiode), a power module, an IC (integrated circuit), and a thermalresistance, and the like can be cited as examples of the mountedcomponent 15. In the present embodiment, an LED is used as the mountedcomponent 15. The three-dimensional molded circuit component 100 of thepresent embodiment is capable of dissipating effectively the heatgenerated by the LED even when an LED which generates a large amount ofheat is used as the mounted component. Moreover, the LED radiates(generates) heat from a rear surface on an opposite side of alight-emitting surface. By arranging the metal part 11 which is a heatdissipating member on a rear surface side of the LED (mounted component15), the three-dimensional molded circuit component 100 of the presentembodiment is capable of dissipating effectively the heat generated bythe LED.

The mounted component 15 is mounted in the recess 13 formed on the basemember 10. One mounted component 15 may be mounted for (with respect to)one recess 13, or a plurality of mounted components 15 may be mountedfor (with respect to) one recess 13. The side wall 13 a of the recess 13is formed by the resin part 12 and the base 13 b of the recess 13 isformed by the resin thin film 16. The mounted component 15 is arranged(disposed) on the metal part 11 via the resin thin film 16. In thepresent embodiment, the resin think film 16 is a portion of the resinpart 12. In other words, in the present embodiment, the recess 13 isformed in the thermoplastic resin layer (resin part 12), and the resinthin film 16 is a portion, having a thin thickness, of the thermoplasticresin layer. Therefore, the resin thin film 16 is formed of athermoplastic resin same as that in the resin portion 12. In the presentembodiment, the metal part 11, and resin part 12 which includes theresin thin film 16 form the base member 10.

From a point of view of heat dissipation, it is desirable to arrange(dispose) the mounted component 15 directly on the meal part 11.However, the direct mounting is difficult, as it is necessary toinsulate the mounted component 15 and the metal part 11. In the presentembodiment, by arranging (disposing) the mounted component 15 on themetal part 11 via the thin resin thin film 16, both of the insulationbetween the mounted component 15 and the metal part 11 and the heatdissipation are achieved.

A thickness t₁₆ of the resin thin film 16 is in the range of 0.01 mm to0.5 mm. Since a resin material has heat insulating properties, when thethickness t₁₆ of the resin thin film 16 is about 1 mm to 5 mm which is athickness of a normal injection molding, the heat dissipation propertyis inadequate. By letting the thickness t₁₆ of the resin thin film 16 tobe 5 mm or less, it is possible to dissipate more adequately the heatgenerated by the mounted component 15, by the metal part 11. Moreover,since the mounted component 15 is electrically connected to the circuitpattern 14, a wiring may be formed by a plating film even on the resinthin film 16. As it will be described later in detail, since laserdrawing (laser lithography) is used for forming wiring made of(including) plating film, the resin thin film 16 is required to have athickness that will not allow piercing through the film by the laserdrawing. Furthermore, the resin thin film 16 of the present embodimentbeing formed by a method such as insert molding, and the like, isrequired to have a thickness that allows the molten resin to flow. Whenthe thickness t₁₆ of the resin thin film 16 is 0.01 mm or more,formation of the wiring using the laser drawing on the resin thin film16 is possible, and molding of the resin thin layer 16 using theinsert-molding is also possible. From the point of view described above,it is preferable that the thickness t₁₆ of the resin thin film 16 is inthe range of 0.1 mm to 0.2 mm.

In a case in which the thickness t₁₆ of the resin thin film 16 is notuniform, an average value (average thickness) of the resin thin film 16is in the range of 0.01 mm to 0.5 mm, and preferably in the range of 0.1mm to 0.2 mm. It is possible to find the average value of the thickness(average thickness) of the resin thin film 16 by measuring the thicknessof the resin thin film 16 at three locations or more than threelocations of a cross-section of the resin thin film 16 in a directionperpendicular to the interface of the resin thin film 16 and the metalpart 11, and calculating an average of the measured values. Moreover,even in the case in which the thickness of the resin thin film 16 is notuniform, it is preferable that the thickness t₁₆ of the resin thin film16 fluctuates (varies) in the range of 0.01 mm to 0.5 mm, it is morepreferable that the thickness t16 fluctuated (varies) in the range of0.1 mm to 0.2 mm. In other words, a region in which the thickness t₁₆ isin the range of 0.01 mm to 0.5 mm, and preferably is in the range of 0.1mm to 0.2 mm, may be the resin thin film 16.

It is preferable that an area of the resin thin film 16, or in otherwords, an area of the base 13 b of the recess 13 is in the range of 0.1cm² to 25 cm² per the mounted component 15 arranged on the resin thinfilm 16. The wider the area of the resin thin film 16, the higher is theheat dissipation effect, but the molding becomes difficult. When thearea of the resin thin film 16 is within the abovementioned range, it ispossible to achieve both of the high heat dissipation effect and theease of molding. In the present embodiment, the resin thin film 16having a high heat dissipation property is restricted (limited) to aportion on which the mounted component 15 is (to be) mounted.Accordingly, a thin-film portion that is hard to mold is minimized, andthe ease of molding is improved, and as a result, the productivity ofthe three-dimensional molded circuit component is improved.

In the present embodiment, the area of the resin thin film 16, as shownin FIG. 2, is an area of a region S₁₆ having a thickness t₁₆ which isthinner than the thickness t₁₂ of the surrounding resin par 12, and isthe area of the base 13 b of the recess 13. The region S₁₆ is notrestricted (limited) to a region which is in contact with the mountedcomponent 15, and may be a region wider than a region S₁₅ which is incontact with the mounted component 15 as shown in FIG. 2.

It is possible to use the recess 13 as a recess for determining amounting position of the mounted component 15. In a three-dimensionalcircuit (stereoscopic circuit), the mounting position of the mountedcomponent has to be determined in three directions, and determining themounting positions is difficult as compared to that in a two-dimensionalcircuit (planar circuit). In the three-dimensional molded circuitcomponent 100 of the present embodiment, by letting the mountingposition of the mounted component 15 to be a recess, detection of themounting position becomes easy. In a case of using the recess 13 as arecess for positioning the mounted component 15, it is preferable tomount one mounted component 15 for (with respect to) one recess 13, andit is preferable that a shape and an area of the base (bottom) 13 b ofthe recess 13 are substantially same as a shape and an area of a surfaceof the mounted component 15 which is in contact with the base 13 b, asshown in FIG. 3. In this case, the area of the resin thin film 16 (areaof the region S₁₆) is substantially same as the area of the region S₁₅which is in contact with the mounted component 15 as shown in FIG. 3.Accordingly, determining the mounting position of the mounted component15 becomes further easier. From a point of view of easing determiningthe mounting position of the mounted component 15, it is preferable thata depth d₁₃ of the recess 13 is in the range of 0.1 mm to 5 mm.

A nickel phosphorous film 18 may be formed on the surface of the metalpart 11 of the present embodiment. Since the nickel phosphorous film 18has a high corrosion resistance, the corrosion resistance of the metalpart 11 is improved.

(2) Method of Manufacturing Three-Dimensional Molded Circuit Component

A method of manufacturing the three-dimensional molded circuit component100 will be described below. Firstly, the base member 10 which includesthe metal part 11 and the resin part 12 is manufactured. In the presentembodiment, the base member 10 is manufactured by the insert molding(integrated molding) in which, the resin part 12 is molded byinjection-filling a thermoplastic resin in a mold in which the metalpart 11 has been arranged in advance. For improving an adhesion of themetal part 11 and the resin part 12, the nano molding technology (NMT),for example, disclosed in Patent Literature 2 or 3, may be used.Moreover, as another method for improving the adhesion of the metal part11 and the resin part 12, a surface shape of the metal part 11 and asurface shape of the resin part 12 may be let to be shapes that are notseparated (disengaged) physically.

In the present embodiment, the resin thin film 16 is a portion of theresin part 12, and the recess 13 is formed in the surface of the resinpart 12. Therefore, in the present embodiment, the resin part 12 whichincludes the resin thin film 16 is molded by using a mold in which aprojection corresponding to the recess 13 is formed inside the cavity.

Next, the circuit pattern 14 which was formed by the plating film on theresin part 12 is formed. A method for forming the circuit pattern 14 isnot restricted to any particular method, and it is possible to use ageneral-purpose method. Methods such as a method of patterning on aplating film by a photoresist, and removing the plating film on aportion other than the circuit pattern by etching, a method ofroughening a base member by irradiating laser light on a portion onwhich the circuit pattern has been formed, or a method of forming theplating film only on a portion irradiated by laser light by applying afunctional group and the like can be cited as the method for forming thecircuit pattern 14.

In the present embodiment, the circuit pattern 14 is formed by a methoddescribed below. Firstly, a catalytic activity inhibiting layer isformed on the surface of the resin part 12. Next, a portion on which anelectroless plating film is to be formed, or in other words, a portionon which the circuit pattern 14 is to be formed, is laser-drawn on thesurface of the resin part 12 having the catalytic activity inhibitinglayer formed thereon. An electroless plating catalyst is applied to thesurface of the resin part 12 subjected to laser drawing, and next, isbrought into contact with an electroless plating solution. In thismethod, the catalytic activity inhibiting layer hinders (inhibits) thecatalytic activity of the electroless plating catalyst applied thereon.Consequently, formation of the electroless plating film is suppressed onthe catalytic activity inhibiting layer. Whereas, the inhibiting layerbeing removed from the laser-drawn portion, the electroless plating filmis formed on the laser-drawn portion. Accordingly, the circuit pattern14 is formed by the electroless plating film on the surface of the resinpart 12.

It is preferable that the catalytic activity inhibiting layer includes apolymer having at least one of an amide group and an amino group(hereinafter, appropriately referred to as amide group and/or aminogroup-containing polymer). The amide group and/or amino group-containingpolymer act(s) as a catalytic activity inhibiter which hinders(inhibits) or lowers (weakens) the catalytic activity of the electrolessplating catalyst. Although the mechanism of how the amide group and/oramino group-containing polymer hinder(s) the catalytic activity of theelectroless plating catalyst is not clear, the amide group and the aminogroup are adsorbed, coordinated, or react with an electroless platingcatalyst, and accordingly, it is presumed that the electroless platingcatalyst cannot act as a catalyst.

It is possible to use (an) arbitrary amide group and/or amino grouppolymer, but from a point of view of hindering the catalytic activity ofa electroless plating catalyst, a polymer containing the amide group ispreferable, and moreover, a branched polymer having a side chain ispreferable. In the branched polymer, it is preferable that the sidechain includes at least one of the amide group and the amino group, andit is more preferable that the side chain includes the amide group. Itis preferable that the branched polymer is a dendritic polymer.Dendritic polymers are polymers formed by a molecular structure in whichregular branches are repeated frequently (at short intervals), and areclassified into dendrimers and hyper branched polymers. A dendrimer is apolymer which has an orderly and perfectly dendritic-branched structurewith a molecule which is a core, as a center, and is a polymer of aspherical shape having a diameter of a few nm, whereas a hyper branchedpolymer, unlike a dendrimer having a perfectly dendritic-branchedstructure, is a polymer which has imperfect dendritic branches. Evenamong the dendritic polymers, the hyper branched polymers beingcomparatively easier to synthesize as well as low-priced, are preferableas the branched polymer of the present embodiment.

The laser light and the electroless plating catalyst to be used forlaser drawing are not restricted in particular, and it is possible touse a general-purpose laser light and a general-purpose plating catalystupon selecting appropriately.

The electroless plating solution is not restricted in particular, and itis possible to use a general-purpose electroless plating solution uponselecting appropriately. However, according to the reasons describedbelow, a neutral electroless nickel phosphorous plating solution ispreferable. Here, the neutral electroless nickel phosphorous platingsolution refers to an electroless nickel phosphorous plating solutionwith a pH in the range of 5.5 to 7.0. According to the study of theinventors, it was revealed that the metal part 11, depending on the typeof a metal used, is eroded by the electroless plating solution, andthere is a possibility (risk) that the metal part 11 is corroded. Forinstance, when an alkaline electroless plating solution is used,although there is no corrosion in a case in which magnesium is used forthe metal part 11, there is corrosion in a case in which aluminum isused for the metal part 11. Whereas, when a neutral electroless nickelphosphorous solution is used, it is possible to suppress the corrosionof aluminum. Therefore, by using the electroless nick phosphorousplating solution, the range of choice of a metal to be used for themetal part 11 is broadened, and it is possible to use aluminum which ischeaper in cost than magnesium, for the metal part 11. Moreover, from apoint of view of improving a plating reactivity, a mildly acidicelectroless nickel phosphorous plating solution having pH in the rangeof 4.0 to 5.5 may be used. In this case, since a speed of growing anickel phosphorous plating film on an aluminum surface becomes fasterthan a speed of eroding of aluminum due to an acidic solution, it ispossible to coat the plating film, and there is no damage caused toaluminum. Although it has been known that corrosion resistance ofaluminum is improved by an anodic oxidation method (alumite treatment)of forming an oxide layer on the surface thereof, the alumite treatmentbecomes a cause of rise in the cost. In the present embodiment, evenwithout using the alumite treatment, by using the electroless nickelphosphorous plating solution for forming the circuit pattern 14, it ispossible to form the nickel phosphorous film 18 on the surface ofaluminum simultaneously with the formation of the circuit pattern 14,and it is possible to improve the corrosion resistance of the metal part11.

In the formation of the circuit pattern 14, an electroless plating filmof other types and an electrolytic plating film may be stacked on theelectroless plating film. At this time, in a case in which the nickelphosphorous film 18 has been formed on the surface of the metal part 11,it is possible to suppress the corrosion of the metal part 11 by theother electroless plating solution or the electrolytic plating solution.

After forming the circuit pattern 14 on the resin part 12, the mountedcomponent 15 is mounted in the recess 13 formed in the base member 10,and is electrically connected to the circuit pattern 14. Accordingly, itis possible to achieve the three-dimensional molded circuit component100 of the present embodiment. A method for mounting is not restrictedin particular, and it is possible to use a general-purpose method. Themounted component 15 may be soldered to the base member 10 by a solderreflow method in which the base member 10 having the mounted component15 arranged thereon is passed through a high-temperature reflow furnaceor a laser soldering method (spot mounting) in which the soldering iscarried out by irradiating laser light to an interface between the basemember 10 and the mounted component 15.

In the three-dimensional molded circuit component 100 of the presentembodiment described heretofore, the mounted component 15 is mounted inthe recess 13 formed in the base member 10. However, the presentembodiment is not restricted to such mounting. For instance, as shown inFIG. 4A and FIG. 4B, when the mounted component 15 is arranged(disposed) on the metal part 11 via the resin thin film 16 having athickness in the range of 0.01 mm to 0.5 mm, the mounted component 15 isnot necessarily required to be mounted in the recess. Even when themounted component 15 is not mounted in the recess, by mounting themounted component 15 in the resin thin film 16, it is possible todissipate adequately the heat generated by the mounted component 15.

As described above, the present teaching provides a three-dimensionalmolded circuit component which has a high heat dissipation property, andmoreover, which can be molded easily and which has a high productivity.

Modified Embodiment 1

Next, a modified embodiment 1 of the present embodiment, shown in FIG. 5will be described below. In the abovementioned three-dimensional moldedcircuit component 100 shown in FIG. 1, the curved metal plate was usedas the metal part 11, whereas, in a three-dimensional molded circuitcomponent 200 of the modified embodiment 1, a heat dissipating fin isused as the metal part 21. An arrangement of the three-dimensionalmolded circuit component 200 is similar to the arrangement of thethree-dimensional molded circuit component 100, except for the heatdissipating fin which is used as the metal part 21. It is possible tomanufacture the three-dimensional molded circuit component 200 by amethod similar to that of the three-dimensional molded circuit component100 except for using the heat dissipating fin as the metal part 21. Inthe three-dimensional molded circuit component 200, by using the heatdissipating fin as the metal part 21, it is possible to improve furtherthe heat dissipation effect.

Modified Embodiment 2

Next, a modified embodiment 2 of the present embodiment shown in FIG. 6will be described below. In a three-dimensional molded circuit component300 shown in FIG. 6, a resin part 32 includes foamed cells 39. Whereas,a resin thin film 36 does not essentially (practically) include thefoamed cells 36. Here, the phrase “the resin thin film 36 does notessentially include the foamed cells” includes a case in which the resinthin film 36 includes foamed cells in a small amount to an extent thatdoes not have an adverse effect on the heat dissipation property of theresin thin film 36 and at the time of reflow, in addition to a case inwhich the resin thin film 36 does not include any foamed cell 36. Inother words, even when the foamed cells are included in the resin thinfilm 36, an amount thereof is small, and a density of the foamed cellsincluded in the resin thin film 36 is lower than a density of the foamedcells 39 included in the resin part 32 in a portion other than the resinthin film 36. An arrangement of the three-dimensional molded circuitcomponent 300 is similar to that of the three-dimensional molded circuitcomponent 100, except for the resin part 32.

By the resin part 32 of the three-dimensional molded circuit component300 of the present embodiment having the foamed cells 39, theweight-reduction of the overall component and improvement in thedimensional precision are facilitated. On the other hand, since theresin thin film 36 does not essentially include the foamed cells 39, theheat dissipation property of the resin thin film 36 is maintained.

A method of manufacturing the three-dimensional molded circuit component300 of the present embodiment will be described below. Firstly, a basemember 30 which includes the metal part 11 and a resin part 32 ismanufactured by the integrated molding. At this time, the resin part 32is foam-molded. It is preferable to foam-mold the resin part 32 by usinga physical foaming agent such as carbon dioxide, nitrogen, and the like.Chemical foaming agents and physical foaming agents are the types offoaming agents, and a decomposition temperature for the chemical foamingagents being lower, it is difficult to foam a resin material having ahigh melting point. It is preferable to use a resin with a high meltingpoint and a high heat resistance. When a physical foaming agent is used,it is possible to foam-mold the resin part 32 by using a resin having ahigh melting point. As a method of molding using a physical foamingagent, it is possible to use MuCell (registered trademark) in which asupercritical fluid and a low-pressure foam-molding method (described inWO2013/027615 Publication) proposed by the inventors, which does notrequire a high-pressure equipment.

In the present modified embodiment, in molding of the resin part 32, amolten resin viscosity is lowered by dissolving the physical foamingagent in the molten resin. Accordingly, a fluidity of a molten resin ina narrow region corresponding to the resin thin film 36 in a mold cavityis induced, and molding of the resin thin film 36 becomes easy.Moreover, in the narrow region corresponding to the resin thin film 36in the mold cavity, a solidification speed of the molten resin beingfast (high), the foamed cells are hard to grow. Accordingly, in theresin thin film 36, the foamed cells 39 are essentially hard to beformed. From a point of view of suppressing the formation of the foamedcells in the resin thin film 36, it is preferable that a thickness t₃₆of the resin thin film 36 is in the range of 0.01 mm to 0.3 mm, and thethickness t₃₆ in the range of 0.01 mm to 0.2 mm is more preferable, andthe thickness t₃₆ in the range of 0.01 mm to 0.1 mm is even morepreferable.

Next, by a method similar to that of the abovementionedthree-dimensional molded circuit component 100, the circuit pattern 14formed by the plating film is formed on the resin part 32. After formingthe circuit component 14, the mounted component 15 is mounted in arecess 33 formed in the base material 30, and is electrically connectedto the circuit pattern 14. Accordingly, it is possible to achieve thethree-dimensional molded circuit component 300 of the presentembodiment. In the present modified embodiment, it is preferable tomount the mounted component 15 by the laser soldering method (spotmounting). For instance, in a case of mounting the mounted component 15by the solder reflow method, it is necessary to pass the base member 30through the reflow furnace at a temperature of 230° C. to 240° C. ormore. At this time, even when a thermoplastic resin having a meltingpoint higher than the reflow temperature is used for the resin part 32,there is a possibility that a surface of the resin part 32 which is afoamed-mold is bloated (bulged, swelled) due to an expansion (bloating)of moisture and the like at the interior. Whereas, in the lasersoldering method (spot mounting), the range which attains hightemperature is minimized. Since a portion to which the laser light isirradiated is the resin thin film 36 in which no foaming cells existessentially (practically), the bloating (bulging, swelling) of thesurface thereof is hard to occur even when heated by the laser light.

Second Embodiment (1) Three-Dimensional Molded Circuit Component

In the present embodiment, a three-dimensional molded circuit component400 shown in FIG. 7 will be described. The three-dimensional moldedcircuit component 400 has a base member 40 which includes a metal part41 and a resin part 42, the circuit pattern 14 which is formed on theresin part 42 by a plating film, and the mounted component 15 which ismounted in a recess 43 formed in the base member 40, and is electricallyconnected to the circuit pattern 14. A side wall 43 a of the recess 43is formed by the resin part 42, and a base 43 b of the recess 43 isformed by a resin thin film 46. The mounted component 15 is arranged(disposed) on the metal part 41 via the resin thin film 46. In the firstembodiment, as shown in FIG. 1, the resin thin film 16 is a portion ofthe resin part 12, and is formed by a thermoplastic resin. Whereas, inthe present embodiment, as shown in FIG. 7, the resin thin film 46 isnot a portion of the resin part 42, and is formed by a heat-curable(thermosetting) resin or a photo-curable resin.

It is possible to use an arbitrary base member for the base member 40,similarly as in the first embodiment, provided that the base member is acomposite body in which the metal part 41 and the resin part 42 arejoined. Moreover, in the first embodiment, the integrated molding inwhich the metal part 11 and the resin part 12 have been moldedintegrally was used, but the present embodiment is not restricted to themolding integrally. For instance, the base member 40 in which the metalpart 41 and the resin part 42 are joined by a joining technology using atriazine thiol derivative, may be used.

As materials of the metal part 41 and the resin part 42, it is possibleto use materials similar to those in the first embodiment. In thepresent embodiment, a metal block is used as the metal part 41.Moreover, in the first embodiment, the resin thin film 16 being aportion of the resin part 12, a thermoplastic resin having a high heatresistance is used for the resin part 12. However the present embodimentis not restricted to the thermoplastic resin. In the present embodiment,the resin thin film 46 and the resin part 42 being formed of differentresins, it is possible to form the resin thin film 46 of a resin havinga high heat resistance and to form the resin part 42 of a resin having alow heat resistance which is comparatively cheaper in price.Accordingly, it is possible to reduce an overall cost of thethree-dimensional molded circuit component 400. For instance, in a casein which the mounted component 15 is not mounted on the base member bythe solder reflow, since the resin part 42 is not sought to have asolder reflow resistance, it is possible to use an engineering plasticsuch as ABS resin (acrylonitrile butadiene styrene resin), apolycarbonate (PC), a polymer alloy of ABS resin and PC (ABS/PC) and thelike. These thermoplastic resins may be used independently or may beused upon mixing two or more types thereof. Moreover, the resin part 42of the present embodiment, similarly as the resin part 32 of themodified embodiment 2 of the first embodiment shown in FIG. 6, may havefoamed cells at an interior thereof. By having the foamed cells at theinterior, weight-reduction of the three-dimensional molded circuitcomponent 400 is facilitated.

It is possible to use the circuit pattern 14 and the mounted component15 similar to those in the first embodiment. The mounted component 15 ismounted in the recess 43 formed in the base member 40. An area of thebase 43 b of the recess 43 and a depth of the recess 43 are similar tothe area and the depth of the recess 13 of the first embodiment.

The resin thin film 46 of the present embodiment is formed by aheat-curable resin (thermosetting resin) or a photo-curable resin. Sincea heat-curable resin and a photo-curable resin before being cured, havea low viscosity, thinning of the resin thin film 46 is easy. Moreover,since a heat-curable resin and a photo-curable resin after being cured,have a high heat resistance and a high density, a heat-curable resin anda photo-curable resin are appropriate as materials for forming the base43 b of the recess 43 to which the mounted component 15 is soldered. Itis preferable that the resin which forms the resin thin film 46 has amelting point of 260° C. or more, and it is more preferable that themelting point is 290° C. or more. As a heat-curable resin, it ispossible to use heat-resistant resins such as an epoxy resin, a siliconresin, a polyimide resins and the like, and as a photo-curable resin, itis possible to use resins such as a polyimide resin, an epoxy resin, andthe like. These heat-curable resins may be used independently, or may beused upon mixing two or more types thereof. Similarly, thesephoto-curable resins may be used independently, or may be used uponmixing two or more types thereof.

The resin thin film 46 may contain an insulating heat dissipatingmaterial. Since the circuit pattern 14 is formed on the resin thin film46, it is not possible to use an inexpensive conductive heat dissipatingmaterial such as carbon. Although the insulating heat dissipatingmaterials are expensive, by including only in the resin thin film 46 onwhich the mounted component 15 is to be mounted, it is possible toachieve both of suppressing a rise in cost and improvement in the heatdissipation property. As the insulating heat dissipating material,ceramic powders which is inorganic powders having a high thermalconductivity are available, and aluminum oxide, boron nitride, aluminumnitride, and the like can be cited as examples. It is preferable thatthe insulating heat dissipating material in the range of 10 wt % to 90wt % is included in the resin thin film 46, and it is more preferablethat the insulating heat dissipating material in the range of 30 wt % to80 wt % is included in the resin thin film 46.

It is preferable that a thickness t₄₆ of the resin thin film 46 of thepresent embodiment is in the range of 0.01 mm to 0.5 mm. When thethickness t₄₆ of the resin thin film 46 existing between the mountedcomponent 15 and the metal part 41 is in this range, it is possible todissipate adequately the heat generated by the mounted component 15 bythe metal part 41, and moreover, the laser drawing on the resin thinfilm 46 is also possible. From the point of view described above,furthermore, it is preferable that the thickness t₄₆ of the resin thinfilm 46 is in the range of 0.01 mm to 0.1 mm, and it is more preferablethat the thickness t₄₆ of the resin film 46 in the range of 0.03 mm to0.05 mm.

(2) Method of Manufacturing Three-Dimensional Molded Circuit Component

A method of manufacturing the three-dimensional molded circuit component400 will be described below. Firstly, the resin thin film 46 which isformed of a heat-curable resin or a photo-curable resin, is formed on asurface 41 a of the metal part 41 (metal block) of the base member 40.It is possible to form the resin thin film 46 by dissolving theheat-curable resin or the photo-curable resin in a solvent therebyletting to be a resin solution, and applying the resin solution to thesurface 41 a of the metal part 41 and drying, and thereafter, heating orphoto-irradiating (exposing to light). Since the resin solution has alow viscosity, formation of the thin film is easy.

Next, the metal part 41 having the resin thin film 46 formed thereon,and the resin part 42 are joined, and the base member 40 ismanufactured. The method for joining the metal part 41 and the resinpart 42 is not restricted in particular, and it is possible to use anarbitrary method. The metal part 41 and the resin part 42 may be moldedintegrally by insert molding and the like, similarly as in the firstembodiment.

In the manufacturing of the base member 40, the side wall 43 a is formedby the resin part 42 around the resin thin film 46. Accordingly, therecess 43 defined by the side wall 43 a and the base 43 b is formed in asurface of the base member 40.

Next, the circuit pattern 14 formed by the plating film is formed on theresin part 42. As a method for forming the circuit pattern 14, it ispossible to use a method similar to that in the first embodiment.

After forming the circuit pattern 14 on the resin part 42, the mountedcomponent 15 is mounted in the recess 13 formed in the base member 40,and is electrically connected to the circuit pattern 14. Accordingly, itis possible to achieve the three-dimensional molded circuit component400 of the present embodiment. A method for mounting is not restrictedin particular, and similarly as in the first embodiment, it is possibleto use a general-purpose method. In the present embodiment, it ispreferable to use the laser soldering method or a local heating methodof heating by a spot heater (spot mounting). By the laser solderingmethod and the local heating method by the spot heater, since only theresin thin film 46 is heated, it is possible to use a comparativelyinexpensive resin having a low heat resistance for the resin part 42,and cost reduction of the overall three-dimensional molded circuitcomponent 400 is facilitated.

In the three-dimensional molded circuit component of the presentembodiment described heretofore, the mounted component 15 is mounted inthe recess 43 formed in the base member 40. However, the presentembodiment is not restricted to such mounting. For instance, the mountedcomponent 15 is not necessarily required to be mounted in the recess,provided that the mounted component 15 is mounted on the resin thin film46 similarly as in the first embodiment mentioned above. Even when themounted component 15 is not mounted in the recess, by mounting themounted component 15 on the resin thin film 46, it is possible todissipate adequately the heat generated by the mounted component 15, bythe metal part 41.

EXAMPLES

The present teaching will be described below specifically by examplesand comparative examples. However, the present teaching is notrestricted to the examples and the comparative examples described below.

Example 1

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by using base member 10 in whichthe metal part 11 and the resin part 12 are integrally molded, and theresin thin film 16 is a portion of the resin part 12. Moreover, an LED(light emitting diode) was used as the mounted component 15.

(1) Manufacturing of Base Member

The base member 10 was manufactured by insert-molding by using analuminum plate for the metal part 11 and an aromatic polyamidecontaining an inorganic filler (Bairo amido GP2X-5 manufactured byToyobo, melting point 310° C.) for the resin part 12.

A mold having a cavity corresponding to the base member 10 which is acurved body in the form of the plate as shown in FIG. 1 was prepared. Athickness of the cavity corresponding to a thickness t₁₀ of the basemember 10 was let to be 2 mm. In the cavity of the mold, a shape of aportion (projection in the cavity) corresponding to the recess 13 waslet to be variable by using a bushing (nesting, bush) in order to beable to vary the thickness t₁₆ and the area of the resin thin film 16.

The aluminum plate having the plate thickness 1 mm was bent to matchwith a shape of the cavity of the mold. For improving the adhesionbetween the metal part 11 and the resin part 12 by the nano moldingtechnology (NMT), a surface of the aluminum plate that was bent wasetched. The etched aluminum plate was arranged (disposed, placed) at anappropriate position in the cavity of the mold, and the base member 10was insert-molded by injection-filling the aromatic polyamide in a freespace in the cavity. For insert-molding, a general-purpose injectionmolding apparatus was used, and the mold temperature was let to be 140°C. and the resin temperature was let to be 340° C. In the base member 10that was achieved, a thickness t₁₁ of the metal part 11 (metal plate)was 1 mm, and a thickness t₁₂ of the resin part 12 was 1 mm. Moreover,by adjusting a size of the nesting (busing, bush) inside the moldcavity, the thickness t₁₆ of the resin thin layer was let to be 0.2 mmand the area of the resin thin film 16 was let to be 0.49 cm² (0.7cm×0.7 cm). The depth d₁₃ of the recess 13 was let to be 1.8 mm.

(2) Formation of Circuit Pattern

In the present example, the circuit pattern 14 formed of the platingfilm on the resin part 12 was formed by a method described below.

(a) Synthesis of Catalytic Activity Inhibitor

An amide group was introduced into a commercially available hyperbranched polymer (Hypertech HPS-200 manufactured by Nissan Kagaku Kogyou(Nissan Chemical Corporation)) represented by formula (1), and a hyperbranched polymer represented by formula (2) was synthesized.

Firstly, the hyper branched polymer (1.3 g, dithiocarbamate group: 4.9mmol), N-isopropylacrylamide (NIPAM) (1.10 g, 9.8 mmol), α,α′-azobisisobutyronitrile (AIBN) (81 mg, 0.49 mmol), and dehydratedtetrahydrofuran (THF) (10 mL) were added to a Schlenk tube (Schlenkflask), and the mixture was subjected to three freeze-pump-thaw cycles.Thereafter, the mixture was stirred and allowed to react overnight (for18 hours) at 70° C. using an oil bath, and after the completion ofreaction, was cooled by iced water (ice-cold water), and then dilutedappropriately by THF. Next, the diluted mixture was re-precipitated inhexane, and a solid product material achieved was vacuum-dried overnightat 60° C. An NMR (nuclear magnetic resonance) measurement and an IR(infrared absorption spectrum) measurement of the product material wascarried out. As a result, it could be confirmed that by introducing theamide group into the commercially available hyper branched polymerrepresented by formula (1), a polymer represented by formula (2) wasprepared. Next, a molecular weight of the product material was measuredby GPC (gel permeation chromatography). Regarding the molecular weight,a number-average molecular weight (Mn) was 9,946 and a weight-averagemolecular weight (Mw) was 24,792, and the number-average molecularweight (Mn) and the weight-average molecular weight (Mw) unique to thehyper-branched structure were substantially different values. The yieldof the hyper-branched polymer represented by formula (2) was 92%.

(b) Formation of Catalytic Activity Inhibiting Layer

The synthesized polymer represented by formula (2) was dissolved inmethyl ethyl ketone, and a polymer solution of polymer concentration 0.5wt % was prepared. The base member 10 that was molded was dipped intothe polymer solution for five seconds at a room temperature, andthereafter, dried in a drier for five minutes at 85° C. Accordingly, acatalytic activity inhibiting layer was formed on the surface of thebase member 10. A film thickness of the catalytic activity inhibitinglayer was approximately 70 nm.

(c) Laser Drawing

A portion corresponding to the circuit pattern 14, on the surface of theresin part 12 on which the catalytic activity inhibiting layer wasformed, was laser-drawn by using a 3-D laser marker (fiber lasermanufactured by Keyence, the output 50 W) at (with) a processing(machining) speed of 2000 mm/s. A line width of a drawing pattern waslet to be 0.3 mm, and the minimum distance between adjacent drawing linewas let to be 0.5 mm. By the laser drawing, it was possible to removethe catalytic activity inhibiting layer on a laser-drawn (laser drawing)portion. Moreover, the laser-drawn portion was roughened, and the fillerincluded in the resin part 12 was exposed.

(d) Application of Electroless Plating Catalyst and Formation of PlatingFilm

The base member 10 subjected to laser-drawing was immersed (soaked) inpalladium chloride solution (Activator, manufactured by Okuno ChemicalIndustries Co. Ltd.) for five minutes at 30° C., and an electrolessplating catalyst was applied. The base member 10 was washed with water,and next, the base member 10 was immersed in an electroless nickelphosphorous plating solution (Top Nicoron LPH-L manufactured by OkunoChemical Industries Co. Ltd, pH 6.5) for 10 minutes at 60° C.Approximately 1 μm nickel phosphorous film (electroless nickelphosphorous film) was grown selectively on the laser-drawn portion onthe resin part 12. At the same time, approximately 1 μm nickelphosphorous film 18 was formed also on the surface of the metal part 11(aluminum plate).

Furthermore, 10 μm electrolytic copper plating film, 1 μm electrolyticnick plating film, and 0.1 μm electrolytic gold plating film werestacked in this order on the nickel phosphorous film of the laserdrawing portion by a general-purpose method, and the circuit pattern 14was formed. In the present example, the circuit pattern 14 was formedeven on the resin thin film 16 without breaking of wire.

(3) Mounting of Mounted Component

The solder 17 and the mounted component (LED) 15 were arranged(disposed, placed) in the recess 13 formed in the base member 10.Furthermore, a solder and a resistance not shown in the diagram werearranged (disposed) on a portion of the base member 10, other than therecess 13. The mounted component 15 and the resistance (not shown in thediagram) were arranged (disposed) at positions electrically connectibleto the circuit pattern 14. Next, the base member 10 was passed throughthe reflow furnace. The base member 10 was heated in the reflow furnace,and the maximum temperature attained of the base member 10 becomeapproximately 240° C., and the time for which the base member 10 washeated at the maximum temperature attained was 30 seconds. The mountedcomponent 15 was mounted on the base member 10 by the solder 17, and thethree-dimensional molded circuit component 100 of the present examplewas achieved.

Example 2

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the thickness of the resin thin film 16, which waslet to be 0.05 mm.

Example 3

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the thickness of the resin thin film 16, which waslet to be 0.1 mm.

Example 4

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the thickness of the resin thin film 16, which waslet to be 0.5 mm.

Example 5

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the area of the resin thin film 16, which was letto be 4 cm² (2 cm×2 cm).

Example 6

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the area of the resin thin film 16, which was letto be 16 cm² (4 cm×4 cm).

Example 7

In the present example, the three-dimensional molded circuit component100 shown in FIG. 1 was manufactured by a method similar to that in theexample 1, except for the area of the resin thin film 16, which was letto be 25 cm² (5 cm×5 cm).

Comparative Example 1

In the present comparative example, the three-dimensional molded circuitcomponent 100 shown in FIG. 1 was manufactured by a method similar tothat in the example 1, except for the thickness of the resin thin film16, which was let to be 0.008 mm.

Comparative Example 2

In the present comparative example, the three-dimensional molded circuitcomponent 100 shown in FIG. 1 was manufactured by a method similar tothat in the example 1, except for the thickness of the resin thin film16, which was let to be 0.7 mm.

[Evaluation of Three-Dimensional Molded Circuit Component]

The following evaluation was carried out for the three-dimensionalmolded circuit components manufactured in the examples 1 to 7, and thecomparative examples 1 and 2. The results are shown in N 1.

(1) Moldability of Resin Thin Film

A moldability of the resin thin film in the integrated molding of thebase member was evaluated according to the following evaluationcriteria.

<Evaluation Criteria for Moldability of Resin Thin Film>

+: An unfilled portion of the molten resin (A portion not filled withthe molten resin) was not developed (generated) in the resin thin film.−: An unfilled portion of the molten resin (a portion not filled withthe molten resin) was developed (generated) in the resin thin film.

(2) Heat Dissipation Property of Three-Dimensional Molded CircuitComponent

A predetermined electric voltage was applied to the three-dimensionalmolded circuit component manufactured, and an LED was lit. An LEDsurface temperature was measured by thermography after one hour afterthe LED was lit. The heat dissipation property of the three-dimensionalmolded circuit component was evaluated according to the followingevaluation criteria.

<Evaluation Criteria for Heat Dissipation Property of Three-DimensionalMolded Circuit Component>

+: The LED surface temperature after lighting the LED for one hour wasnot more than 100° C.−: The LED surface temperature after lighting the LED for one hour wasmore than 100° C.

TABLE 1 Heat dissipation Resin thin film property Thickness AreaMoldability of (LED surface (mm) (cm²) resin thin film temperature)Example 1 0.2 0.49 + + (80° C.) Example 2 0.05 0.49 + + (70° C.) Example3 0.1 0.49 + + (75° C.) Example 4 0.5 0.49 + + (95° C.) Example 5 0.24.0 + + (78° C.) Example 6 0.2 16 + + (75° C.) Example 7 0.2 25 + + (70°C.) Comparative 0.008 0.49 − N/A example 1 Comparative 0.7 0.49 +  −(105° C.) example 2

As shown in table 1, in the examples 1 to 7 in which the thickness ofthe resin thin film is in the range of 0.01 mm to 0.5 mm, both themoldability of the resin thin film and the heat dissipation property ofthe three-dimensional molded circuit component were favorable. When theexamples 1 to 4 in which only the thickness of the resin thin filmdiffers, were compared, it was revealed that, the thinner the thicknessof the resin thin film, the lower is the LED surface temperature afterlighting the LED for one hour, and the higher is the heat dissipationproperty of the three-dimensional molded circuit component. Moreover,when the example 1 and the examples 5 to 7 in which only the area of theresin thin differs, were compared, it was revealed that the larger thearea of the resin thin film, the lower is the LED surface temperatureafter lighting the LED for one hour, and the higher is the heatdissipation property of the three-dimensional molded circuit component.The larger the area of the resin thin film, the more difficult it is tomold the resin thin film. However, even in the example 7 in which thearea of the resin thin film is 25 cm², the unfilled portion of themolten resin (the portion not filled with the molten resin) was notdeveloped (generated), and the moldability was favorable.

Whereas, in the comparative example 1 in which the thickness of theresin thin film is 0.008 mm which is thin, the unfilled portion of themolten resin (the portion not filled with the molten resin) wasdeveloped (generated), and the moldability was poor. Therefore, in thecomparative example 1, evaluation of the heat dissipation property ofthe three-dimensional molded circuit component was not carried out. Inthe comparative example 2 in which the thickness of the resin thin filmis 0.7 mm which is thick, the heat dissipation property of thethree-dimensional molded circuit component was poor.

Example 8

In the present example, a three-dimensional molded circuit component wasmanufactured by a method similar to that in the example 1, except for aheat dissipating fin made of aluminum which was used instead of thealuminum plate, as the metal part. In other words, the three-dimensionalmolded circuit component manufactured in the present embodiment is thethree-dimensional molded circuit component 200 shown in FIG. 5.

Evaluation of (1) the moldability of the resin thin film and (2) theheat dissipation property of the three-dimensional molded circuitcomponent was carried out similarly as in the example 1. The moldabilityof the resin thin film was favorable. The heat dissipation property ofthe three-dimensional molded circuit component was favorable, and theLED surface temperature after lighting the LED for one hour was 70° C.,which is 10° C. lower than that in the example 1. From this result, itcould be confirmed that the heat dissipation property improves by usingthe heat dissipating fin for the metal part.

Example 9

In the present example, the thickness of the resin thin film was let tobe 0.15 mm, and the resin part of the base member was foam-molded, andthe mounted component (LED) was mounted on the base member by the lasersoldering method (spot mounting). Except for the abovementioned points,a three-dimensional molded circuit component was manufactured by amethod similar to that in the example 1. In other words, thethree-dimensional molded circuit component manufactured in the presentexample is the three-dimensional molded circuit component 300 shown inFIG. 6. In the present example, the base member was integrally molded byinsert-molding by using a mold similar to the mold used in theexample 1. A molding apparatus disclosed in WO 2013/027615 Publicationwas used as the molding apparatus, and the resin part was foam-molded byusing pressurized nitrogen as a physical foaming agent. A fillingpressure of nitrogen was let to be 10 MPa, and a backpressure-valvepressure of a vent pressure reducing portion was let to be 6 MPa.

A specific gravity of the resin part 32 of the three-dimensional moldedcircuit component 300 that was achieved, became approximately 8% loweras compared to that of a solid (non-foamed body). A cross-section of theresin part 32 and a cross-section of the resin thin film 36 wereobserved by a microscope. A cell diameter of the cells 39 of the resinpart 32 was in the range of 30 μm to 80 μm which is minute. Whereas, thefoamed cells were not discovered (found) on the cross-section of theresin thin film 36. In other words, the resin thin film 36 did notessentially (practically) include the foamed cells. Moreover, in thelaser soldering (spot mounting) of the mounted component (LED), nobloating (bulging, swelling) was observed on the resin thin film 36 towhich the laser light was irradiated.

Furthermore, an experiment of irradiating laser light same as that usedin the laser soldering method (spot mounting) to the resin part 32including the foamed cells 39, of the three-dimensional molded circuitcomponent 300 achieved, was carried out. When the laser light wasirradiated, bloating (bulging, swelling) occurred in the resin part 32including the foamed cells 39. From this result, it was revealed that bycarrying out the foam-molding, the heat resistance of the resin part 32was lowered, however, by not forming the foamed cells in the resin thinfilm 36, it is possible to maintain the heat resistance of the resinthin film 36 on which the LED is mounted. In the three-dimensionalmolded circuit component 300 of the present example, the overallcomponents were made light-weight successfully while maintaining theheat resistance of the LED mounting portion (portion on which the LED ismounted).

Example 10

In the present example, the three-dimensional molded circuit component400 shown in FIG. 7 was manufactured by using the base member 40 inwhich the metal part 41 and the resin part 42 are integrally molded, andthe resin thin film 46 is formed of a heat-curable (thermosetting)resin. Moreover, an LED (light emitting diode) was used as the mountedcomponent 15.

(1) Manufacturing of Base Member

An aluminum block was used for the metal part 41, and an aromaticpolyamide containing inorganic filler similar to the resin used in theexample 1 (Bairo amido GP2X-5 manufactured by Toyobo, melting point 310°C.) was used for the resin part 42. Moreover, for the resin thin film46, a polyimide which is a thermosetting (heat-curable) resin containingboron nitride powder having an average particle diameter (particle size)of 4 μm as an insulating heat dissipating material was used.

Firstly, polyamide acid which is a polyimide precursor and boron nitridepowder were dispersed and dissolved in N-methyl-2-pirolidone (NMP), anda resin slurry solution having polyimide concentration (solid-contentconcentration) 12 wt % and boron nitride concentration 50 wt % wasprepared. The resin slurry solution prepared was applied to the surface41 a of the metal part 41, and was hardened (cured) by heating at 350°C. for 30 minutes, and the resin thin film 46 was formed. An area of theresin thin film 46 was let to be 1 cm² (1 cm×1 cm), and the thicknesst₄₆ of the resin thin film 46 was let to be 20 μm. Moreover, the contentof boron nitride in the resin thin film 46 was let to be 70 percent byvolume (70 volume percent).

A mold having a cavity corresponding to the base member 40 shown in FIG.7 was prepared. A portion (projection in the cavity) corresponding tothe recess 43 was provided in the cavity of the mold. For improving theadhesion between the metal part 41 and the resin part 42 by the nanomolding technology (NMT), a surface of the metal part 41 (aluminumblock) was etched. The etched aluminum metal part 41 was arranged(disposed, placed) at an appropriate position in the cavity of the mold,and the base member 40 was insert-molded by injection-filling thearomatic polyamide in a free space (region) in the cavity. Forinsert-molding, an injection molding apparatus similar to that in theexample 1 was used and insert-molding was carried out with similarmolding conditions (mold temperature 140° C., resin temperature 340°C.). The recess 43 defined by the side wall 43 a formed by the resinpart 42 and the base 43 b formed by the resin thin film 46 was formed inthe base member 40 that was achieved. The depth of the recess 43 was letto be 1.8 mm.

(2) Formation of Circuit Pattern and Mounting of Mounted Component

By a method similar to that in the example 1, the circuit pattern 14formed by the plating film on the resin part 42 was formed. In thepresent example, the circuit pattern 14 was formed even on the resinthin film 46 without breaking of wire. Next, by a method similar to thatin the example 1, the mounted component (LED) 15 was mounted in therecess 43 formed in the base member 40. Accordingly, thethree-dimensional molded circuit component 400 shown in FIG. 7 wasachieved.

The heat dissipation property of the three-dimensional molded circuitcomponent was evaluated by a method similar to that in the example 1.The heat dissipation property of the three-dimensional molded circuitcomponent was favorable, and the LED surface temperature after lightingthe LED for one hour was 65° C., which was 15° C. lower than that in theexample 1. From this result, it could be confirmed that the heatdissipation property improves by making the resin thin film thin, andfurthermore, by containing a heat dissipating material. Moreover, itcould be confirmed that it is possible to manufacture a thin resin thinfilm easily by using a thermosetting resin.

Example 11

In the present example, a three-dimensional molded circuit component wasmanufactured by a method similar to that in the example 1, except forusing a strongly-basic electroless copper plating solution (manufacturedby Okuno Chemical Industries Co. Ltd., pH 12) instead of the neutralelectroless nickel phosphorous plating solution in the formation of thecircuit pattern.

A surface of the metal part (aluminum plate) of the three-dimensionalmolded circuit component achieved in the present example was corroded,and copper was precipitated (deposited) on a portion thereof. Adhesionof the copper precipitated (deposited) was low, and was peeled off(exfoliated) easily. The heat dissipation property of thethree-dimensional molded circuit component was evaluated by a methodsimilar to that in the example 1 after removing by peeling off(exfoliating) the copper and the corroded portion of the surface of themetal part. The heat dissipation property of the three-dimensionalmolded circuit component of the present example was favorable, and theLED surface temperature after lighting the LED for one hour was lit was80° C. which is same as in the example 1. From this result, it wasrevealed that the corrosion of the metal part occurs when aluminum isused for the metal part and a strongly-basic plating solution is usedfor the plating solution. However, it could be confirmed that when thecopper and the corroded portion of the surface of the metal part areremoved, there is no problem in practical use of the three-dimensionalmolded circuit component.

The three-dimensional molded circuit component of the present teachinghas a high (superior) heat dissipating property, and moreover, is easyto mold and has a high productivity. Therefore, it is possible tosuppress the temperature of the three-dimensional molded circuitcomponent from becoming high due to generation of heat by a mountedcomponent such as an LED and the like. The three-dimensional moldedcircuit component is applicable in smart telephones and automobilecomponents.

What is claimed is:
 1. A three-dimensional molded circuit component,comprising: a base member which includes a metal part and a resin part;a circuit pattern which is formed on the resin part; a resin thin filmwhich is formed on the metal part, and which includes one of athermosetting resin and a photo-curable resin; and a mounted componentwhich is mounted on the resin thin film, and is electrically connectedto the circuit pattern, wherein the resin thin film has a first surfaceand a second surface opposing each other, the first surface of the resinthin film is formed on the metal part, and the second surface of theresin thin film is formed with a part of the circuit pattern, on whichthe mounted component is disposed, the mounted component is electricallyconnected, by a solder, to the part of the circuit pattern formed on thesecond surface of the resin thin film, on the base member, a recess isdefined by a side wall formed by the resin part and a base formed by theresin thin film, the mounted component is mounted in the recess, and athickness of the resin thin film is in the range of 0.01 mm to 0.5 mm.2. The three-dimensional molded circuit component according to claim 1,wherein the resin thin film contains a heat dissipating material havingan insulation property.
 3. The three-dimensional molded circuitcomponent according to claim 1, wherein the mounted component is a lightemitting diode.
 4. The three-dimensional molded circuit componentaccording to claim 1, wherein a nickel phosphorous film is formed on asurface of the metal part.